Method of fixing nitrogen.



J. E. BCHER. METHOD 0F FIXING NITROGEN. APPLICATION FILED Nov.1,1913.

Patented Dec. 15, 1914.

/ZY Hor/yay J. E. BUCHER. METHOD 0F FIXING NiTRoGBN.

v APPLICATION FILED NOV. 7. 1913. 1,120,682. Patented Dee. 15,1914.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.,-

JOHNY E. BUCHER, O'I COVENTRY, RHODE ISLAND, ASSIGNOR To NITROGENPRODUCTS OOMIANY, OFIROVIDENCE, RHODE ISLAND, A CORPORATION or RHODElISLAND.

:BIETHOD OF FIXING NTROGEN.

T o all "whom it may concern-1:v

Be lit known that I', JOHN Bignami, a citizenl of the .United fsb-tetes,residing at Covent'rigin the countyfof Kent and' State of Rhode anduseful Improvements V1n -Methods of Island, have -inif'ent-ed certainnew Fixing Nitrogen, of whieh'the following is This invention relates17o-fthe fixation of .nitrogen and more-partieularly to improve- 'ment'sin the prooesses described 1n my pendingA applic-ations forjUnited:States Letters Patent, respectively designated Serial No..

726,924, filed OetoberfZl, v1912, and Serial No. .737,368 led'Deoember18,1912.

In Operating rny former proeesses upon a la. rigersealeencountered-@erwin diflvieulties fferted to; and .the methodendnieansfor avoiding or'fo'vereoming Whi'hfl have herein "set 'forthwith-siren.particulnrity as-to :enable those 'skilled inthe`-nfpt top izzictise myin- `I'ention.

'The`v 'presentsi-ipi'eeess. Ii-'ilii-e .involving broadly 'ther.pievisionof the..:extentied..eats-A lytie solution? surface f throughthefinstrumentsiity10ft ifi/'hat .may properly. termed gb'riquets.*These ingirnniessto'snid briquets ,after the cyan-l Ogen compound'sought`v has vbeen formed thereu'ithin. I have 'also found 'that theprocess is .'-fi- \f'ii1uteiially favored by pre heating the gaseous.material, e. g. free nitrO gen, as well as the solidmateril, e. g., 'theliriquet-s themselres; the latter advantageously Containing all of theelements requi .site Y.for the. rencti-onexeept the nitrogen, :indfurlmr n v introducing certain kinds of said Jus uuml-,rial in :Iparticular iminner, as `Ii si' described. Indeed` in certain ermestimportance as to here the. f fuses enter the ihi-arg'rs in the. rrtorts:ind undeficonditions they @Su-(ipe from these tu l is liighij.' i bleto prei or theV equivalent 0' uw processi!) becomes a, matter ofvSpecification of Letters Patent. Patented'Dej-i, 1914 Application filednovember 7, 131:1.v seal No. 799,798. 5

.vde 2 1' ready ofibth. nitrogen-and adequate heat to the wholeA`Off1thel'eatslytc` solution surface, which' letter may -be' milde.ton-peI-niete the enti-re vlhzn-'e also rimedi to provides using'but.few and inexpensive -nfia,t,e1*i"=ls, .prfee-RblY.. such alodumCarbonaf '.dii'rolducergas anees.

I Ia'turea enti-on' I willl thereof S0 that.

1lili-@ving thus indi. and Objects of the present now` set 'forth thepa'rti'vu e ditions thoroughly c'Onsisteut-esults nmybe A 'As in' mypreviously "described 'proesses I eonteniplateffixingni'Ogenbyetlfecting ai reaction betweenv reeer 4'tinospherie,nitro-' gen,an element. 'capbl' f' ig 'as the,... base :of .a Oyanogenfeoi pe' a dsuch [as CIf'a-nidmidfearboni tll Ice .offwhtv-'' maybe Uened,.sueli'as." iron enthe lile,2 iv 'solving Oreoibin dei;vl it"react 1e.nder 'emily est dei Athe .course A ably effected ut u.'..tem'p'erature.below the euteetievpoint of the eai'hononteiningiron vto treatment to orin the saine into briquets having; .o rtain deiLiitecharacteristics which rineulariy adapt 'them to a commercial nocess; andt" i 'tion of the matei i Mtion in the acti.

or e nier; be, will i oc `Yed, Lne description being 1n aoe' Witheet:practice.

Prpa/,vizitan of pounds oi 1ron r ash; the product sought being in thiscase sodium cyanid A. portion of the so prepared iron was ground linerand it then gave excellent results in such a mixture as the above; thecyanid resulting from the subjection of the iron-coke-soda ash mixtureto proper temperature, such as is hereinafter referred to,beingseparated from the idues of the reaction bv lixiviation. The saidresidues consisted, oi course, of a mixture. of iron and cole and weremost advantaggeously used over again in the process by grind g themixture preferably for irorn two to five hours in the mill. As thegrinding of commercial cast iron turnings tothe required iineness W asound,`with the grinding apparatus available, to be a tedious operation,l have found it desirable to use commercial iron scale when ope-ratingwith large quantities..

or the above Work over three tons of the scale were readily lground inwhat is known aser. Abba niill to a ineness such that about. 99 percent. passed through a sieve of '1190i' mesh to the inch. This powderWas their mixed with ground coke, usually, in the proportion of poundsof scale to 8O pounds of col-:e for each charge for the inill. Thegrinding o; ch a charge is usually preferably continuo@ for severalhours and it is `then mixed with soda ash, commonly in the proportion550C- pounds of tbe iron-coke mixture to ,'jounilf of soda ash. Tlnslastmixture uns then other heated with nitrogen to luce both cyanidandmetallic iron, Mithout nitrogen, to produce nietallic iron alone, dln either case the so pre-,pwl niass was thoroughly lixiviat-ed b',Shing in lots of 80% to 1000 l ids on 'vacuum filter, lt was again driedand again gro-und for four or five hours the niill L "he iron-eoliemixture so produced was extremely reactive and aforded a cheap and easyWay of producing the greatly extended catalytic solution surfacereferred to in my said patent application.

The eolie which l have heretofore used,

1 over the top of the charge and penetrates contained about seven percent. of ash; and the iron scale, containing sonie oil, Was used just asit eamo Without being` separated magnetically or otherwise from thethree cent. or more of sand and pebbles with which it was contaminated.Neither oil, ash, mineral matter or sulfur in the inaused seemed toatleet the subsequent operations in any very notices y deleterious Way;a feature, it should be noted, of value.

After the above materials have been used once and have been lixiviatedthoroughly, the cyanid produced in subsequent operations no longer givesblack sullid precipitate With silver nitrate upon titration but theprecipitated siler cyanid is pure White in color.

Nearly all of the Work described below in which metallic iron Was used,was clone With a mixture of about equal parte of iron and eolie preparedas above speciiied; while all of the herein described operations inwhich iron scale Was used instead of metallic iron, `were carried outWith the mixture having about the roportion of 70 parts of scale toparts oi) coke.

Prepara-tion of bm'guesf-ln the first of my Cri-pending applicationsabove referred to, it is shown that cyanid formation takes place veryrapidly when the charge is used the forni of powder and in thin layers,but when it is used in thicker layers in iron pipes, action is muchslower because` the nitrogen has to penetrate through a thicker layer ofcharge. Also, the charge of powder shrinks considerably in bulk when thealkali carbonate, or its equivalent, melts; so that a deep channel isformed and the rapid current of nitrogen containing gases flows fintothe interior thereof but slowly. I have cfound that in operating with apulverulent charge disposed in horizontal tubes l() feet longr by 2inches in diameter, the absorption or" nitrogen is quite rapid at iirst,but it then becomes slower and may taire about two and one half hours toobtain aresidue which when lixiviated gives a solution which titratesfor sodium cyanid of substantially 100% purity and which gives noprecipitate with calcium chlorid; such absence of precipitate, ofcourse, indicating the absence of sodium carbonate. When the charge isheated in vertical tubes or other suitable containers and the nitrogenis passed into the base of the charge itself, preferably 'through anumber of suitable small openings, iig/causes the formation of smalltubular channels or lines in the mass While at the saine time largely,if not indeed. entirely, preventing the geyser-like action, hereinafterreferred to, before the :nass becomes plastic by the melting the alkaliycorn- Y pound, or the equivalent olf such compound.

l may here state that l ain aware that iso various other materials thansodium carbonate are adapted for use in my process. Thus, bariumcarbonate may be employed and indeed practically all of the earbonate'sand hydiates of the alkali metals and many of the correspondin or likecpmpounds, of, for example, the al aline earthv metals; the essentialthing to be observed being that some metal or element, e. g. sodium, besupplied,`-preferably from a convenient source of the same such as thecarbonate of sodium; the said metal or the said compound thereof to becapable of participating in the cyanegen-compound-forming reaction,under the conditions of the operation, and of acting as the base of astable cyanogen compound under said conditions.

P `Vertical tubes or retorts are usually far Ihore eective thanhorizontal ones, because the nitrogen current is more readily made topenetrate into the interior of the charge rather than to simply passover it, or at most, to penetrate but little thereinto.

The lines in the charge above .referred to,

'may also be made by thrusting Wires through the mass;

especially after it has b'ecome plastic, and `obviously the introductionof nitrogen may be effected in many Ways. Preferably, however, nitrogenis introduced under a light but positive pressure, so that there is nogradual compression of a considerable volume of this gas followed bysubsequent more or less explosive or `geyser-like actions as the chargeconfining the gas gives way. l't is hence moreover advantageous to usethe charge in briqueted'form to avoid the disadvantages inhercnt in theuse of powders, since with the latter there is a liability to cloggingof the small openings which admit the nitrogen; or even of clogging ofthe retort or large tube itself. with the consequent disturbance of theprocess; v'rhile. further, a sintered charge in the retort may besomewhat diliicult to remove.

Upon trial of powdered charges of the above description. iu continuouslyacting furnaces of the type hereinafter described, the difficulties werefound to be much greater than were subsequently encountered whenbriqueted charges were used; While further with the pou der. undermechanical force, including the action of gravity, the heated chargebecame` compacted or gradually briqueted so that after cooling, it wasvery difficult to remove it with an iron chisel'and hammer. Thisbehavior of the powdered charge showed the possibility of brique'tingthe iron-coke-soda ash mass at a temperature. above the melting point ofthe soda ash; and accordinglyv an iron pot was filled with the reactivemixture containing one part each of iron--coke and soda afsh, the potbeing covered to exclude air as much as It was 2then heated to redness(abot'QOOo C.) and the plastic mass was pressed lirmly with an ironpestle. The resul-ting briquet, in which a little cyanid had alreadybeen formed b v slight contact with the air, Was found after cooling, tobe very firm and adapted to be handled or even thrown about Withoutbreaking.

Experiment 1: This briquet was then broken into coarse fragments andheated in a current of nitrogen in a one half inch iron tube, to1000"-1050O C., for l() minutes. The evolution of carbon monoxid vvasver)Y rapid at first but had practically ceased at the end of this shorttime. After cooling. the briquet fragments ivere lixiviated and the soobtained solution titrated for sodium cy'auid of 100% purity and gave noprecipitate With calcium ehlorid. The titration showed these briquetfragments to contain 7.4% of sodium eyanid. Y

Experiment l showed that briqueting for cyanid work could be donewithout the addition of 'any foreign binder, such as tar or the like;the alkali compound, or its equivalent, itself acting as the bindingmaterial, and that the briqueting could be effected at a relatively hightemperature; thus dispensing with the addition of Water to get therequired plastic condition and avoiding the expense 'of subsequentlyagain evaporating this Water. Briquets thus prepared can be charged intothe furnace before they have cooled, or they may even be made directlyin a suitable cyanid-producing furnace; thus giving the vadded advantageof handling the charge preheated to the temperature of cyani'd formationsubstantially at the 'time of its introduction into the reaction zone ofsaid furnace. Also, pressing of the hot plastic mass causes a greatdecrease in volume and hence must give closer Contact of tlle iron andcoke particles, or tle equivalents of these materials; thus aid ing inproducing' and maintaining a most efficient catalytic solution surface.The very rapid formation of cyanid under these prescribed conditionsshows great efficiency and it also admits lof particularly freie accessof nitrogen to the interior of the charge through the intersticesbetween the individual briquets; an advantage which can scarcelv be overestimated.

The `fact that in the just cited experiment. the-7.4% 'of sodium eyanid(theory about 37%) in the briquets represents practically all of thealkali compound left in the mass, demonstraties thevery greatlyincreased volatilization of the alkali compounds (and of course i'n likemanner of their equivalentsl owing to the large exposure of surface fromwhich evaporation can take place. This notI only7 aids cyanid formationand gives a high purity: but facilitates the removal `thereafter of the'yauid from said briquet by mcuum distillation when the latter is duringthe entire time. Upon cooling, the mass was found to contain 14%,cyanidoff 80% purity.

Experiment 5: This experiment was made to test the eiliciency of a 900pound lot of the 212:1 iron-coke-soda ash briquets which were preparedfrom a ground. cast iron-coke' mixture which had been used and re-usedseveral times for cyanid preparation as above described. Here, l'150grams of the briquets were heated in a horizontal 1 inch pipe in acurrent ofnitrogen at from 680o C. to 960 C. for 15 minutes. The evoluftion of carbon monoxid Was very pronounced at 680Q C. and continuedvigorously for about 5 minutes during which the temperature rose to 870C.; While in 5 minutes more the temperature had reached 900o C. and thereaction had become quite slow. The residue of very hard briquetscontained 15% of sodium cyanid of 85% purity.

Experiment 6: This experiment Was a duplicate of Experiment 5 exceptthat the temperature was further allowed to rise to 1010o C. and thetime of heating was somewhat longer. The action was largely over, evenbefore 860 C. was attained, at which temperature observations began. Thebriquets, upon analysis, were found to contain 16.4% of sodium cyanid.

In Experiments 5 and 6, the nitrogen absorption was so rapid that I hadscarcely any time to make records of the changes taking place, and thereaction was in large measure completed in less than 10 minutes :uidbefore the temperature had reached 000 C.

The preceding experiments were all made in 1 inch iron pipes Where theheat and the nitrogen would have ready access to the'interioi' of thecharge of briquets.

Experiment 7: In two 6 inch horizontal pipes charged with 180 pounds ofverv,good 2: 2 1 iron-coke-soda ash briquets only 4 to 8% of sodiumcyanid was obtained in the residue even upon heating for a number ofhours at a temperature favorable for cyanid formation. As a furthertest, 25 pounds of good 2 2 1 briquets from the same lot that was usedfor Experiment 2 were heated in a current' of nitrogen in a 6 foot pieceof a 6 inch horizontal pipe at' a temperature ranging from 10000 to1G50Q C. for about'one hour and twenty minutes; and upon cooling andexamining the charge it Was found to have settled so that there was aychannel about inch deep in the upper part of the tube. The verticalsection at the end Where the nitrogen entered had a sodium cyanidcontent of 9.5%, While the vertical section about one quarter Waythrough this end of the charge averaged only 3.5% of cyanid. Thevertical sert-ion taken from the middle of the charge showed a cyanidcontent of 12.5%

in a narrow layer at its top, where the nitrogen current passed over it,and about 3% in the broad intermediate layer; while at the bottom ofthis section only 1.4% of sodium cyanid was found. This is illustrateddiagrammatically in Fig. 7 and it shows the average cyanid content orqthe entire charge to be very low. Evidently the settling of the chargeformed a channel, so that the nitrogen could pass therethrough over thetop of the charge and not to any material extent through it, and thisaction was probably greatly intensified by the counter currents ofcarbon monoxid which flowed upward through the charge. Experiments with20 pound charges of iron-scale-coke soda ash in this horizontal 6 inchtube gave similar results.

Experiment 8: In this experiment the same 6 foot long, 6 inch diameteriron pipe was charged `with briquets as before. but Was placed in avertical position in the furnace. In this case 50 pounds of 1: 1: 1 ironcoke-soda ash briquets were heated in the itrogen current, entering atthe bottom of iilhe pipe, for 1 hour and 10 minutes at from 1000o C. to1090o C. The reaction was not completed when the experiment Was stopped,but even so, the top of the charge contained 24% of sodium cyanid whilethe bottom contained 20%. This shows conclusively that the vertical pipeacts very efficiently even when its diameter is 6 inches. It is alsoevi. dent that 10 pounds of sodium eyanid can be produced, per run,eiiiciently in a 6 foot tube of this diameter.

Experiment 9: In this case 55 pounds of briquets composed of about 22pounds of iron scale, 24.- pounds coke, and 9 pounds of soda ash wereheated in a nitrogen current in the vertical 6 inch pipe.y as inExperiment 8, for 2 hours at from 1000 C. to 1100 C. Action at the endof this time was slow and incomplete. f The tube was then allowed tocool and small sections, taken at diilerent levels, were examined. Thetop section contained 28% of sodium cyanid of` 87% purity; othersections from the top to the bottom contained respectively 16, 14, 12and 10% of cyanid; the purity of these four sections varying'l from 90%to 93%. The central part of the lower section contained moderately firmhard briquets whose cyanid content Was 12% of substantially 100% puritywhile the outside part of this lower section was partly disintegratedand contained only 7% of sodium cyanid. This change in concentration of,forexample, alkali compounds is very important and is showndiagrammatically in Fig. 6. In this experiment, all, or nearly all, ofthe required heat was supplied to the charge on the outside andconsequently much volatilization of the alkali material tok place in thehotter outer layers; resulting in a disintegrating of these layers asthe alkali volatilized; While the inner part of the section. which Wasfirmer, contained more alkali. The experinient besides showing theapplication of briqrloting;- to a method of fixing nitrogen. and ifdesired, of simultaneously producing pure iron, is also of greatimportance in showing the conditions necessary for efficient ell'ectu1ation of the process in a continuously acting furnace.

Experiment 10: AA vertical l inch iron pipe was used and a pyrometercontained in a inch iron pipe was pressed into the center of the chargewhich was composed of 8 pounds of 2:2:1 ironcolie-soda ash briquete.lVhen the pyrometer in the outer furnace read 103 o C. the inner oneread 150O C. ln 410 minutes more the outer one read 1080O (l. While theinner indicated S80o C. It then took about 2() minutes nfore for theinside teinpin'ature to rise to 16510o While the outer reading remainedconstant. This shows the slow rate of heatpenetration. through thecharge and it also shows the variations in action caused by varying therate of flow of nitrogen. ln this experiment when the heat was stopped,the product was found to contain 17% of sodium cyanid of 99% purity.

Experiment 11: A 1 inch iron tube was charged with 150 grains of cokeand then 150 grams of iron scale-cokesoda ash briquets o-f thecomposition used in Experiment 8 was introduced. The tuo layers oi' theabove materials were kept separate by using gauze screens and the tubewas then heated in a horizontal furnace from 910o (l. to 1010o C. for 30minutes'and a current of air was passed into the end of the tube containing the colic. The process so conduct-ed was found to ne fairlycilicient as the briquets contained 12.7% of sodium cyanid of aboutpurity. Upon lixiviation, they yielded a clear aqueous solution, showingno yellow color and no lampblack-like carbon floated upon the water. Theyield was as good as that which l had obtained when using nitrogen gas.prepared by passing air over hot copper. with these briquets..

It may oe Well to note here that all temperatures referred to in this.specification were measured with a thermo-electric pyrorneter, placednear the pipes in which the reaction Was taking place.

The above experiments also show the de sirability of 'using acontinuously acting furnace for the briquets which become plastic at thetemperature of cyanid formation; together with the co-acting advantage,so to speak, of so disposing theJnateif-ial that pri marily gravity, or.its equivalent, lateral pressure, shall aid in maintaining an eilicientdistribution of the nitrogen current throughout the bulk of the reactiveAguess, in contradistinction to so disposingl the said 1,12ole82 shownin Experiment i' and Fig. T.A

In general. the furnace construction should pern'iit, in part at least,the trans formation of the carbon InonoXid formed in the cyanidproducing zo'ne, into carbon dioxid Within the charge itself in such aivay as to utilize the extra heat thus pro duced by the fornmtion ofcarbon dioxid while at the same time avoiding the deleterious effect ofthe latter gas 'upon the cyanid. It should also avoid the loss of alkalior the like and the consequent disintegration of the briquets atoneplace and the flooding with the alkali, or like cour pounds, of portionsof the catalytic solution surface at another place or places; .vhilenevertheless retaining; the great aflvantage of rapid circulation of thesaid alkali or its equivalent. In connection witl these last mentionedfeatures attentioi'i may again be directed with advantage to Experiment9 and also to Fig. G of the drawing.

In the drawings which forni a part hereof and in which like referenceclniracters designate like parts throughout the several views l haveexemplified certain preferred furnace construction 'which are adaptcdfor the effectuation of my process in accordance 'with the. abovedescribed conditions. l nl aware, however, that various changes andmodifications may be made in the furnace construction wher-objetodifferently establish the prescribed conditions for effectuating mycommercial process; and l am also aware that various minor changes andmod ilications may be made in 'thc manner of efl'ectuating the processitself without departing from the spirit of my invention. l hence desireto be limited only by the scop of the claims appended hereto; saidclaims being broadly construed in the light of my disclosure. l

Drawings.e-Rcfcrring now to the draw ings. in which like characters ofreference designate like parts: Figure 1 1. Y section of a inutilefurnace provid-wl v retort- \vithin 'which the cjanid forming rcactionmay be effected. Fig. i? s :i detail transverse section talrcn ou linellMilY of Fig. 1. Fig. 3 is a :lr-tail vertical section taken on lineIll-will of Fig. 1. p l is a perspective view oi a traum-ent ol' 'idouble Walled or ainiulusliive retort which may be employed inconnection with my process, Fig'. 5 is a soi-uevvhai'. diag animatievertical fvction of a modii'icd furnace construction. .i ingr thepossible The retort 1, shou'n in Figs. 1, 2 and 3 may be of cast ironand is preferably made of :i relatii ely long t3 inch pipe which isllattened doa'n for the greater portion of its length until its interiordimensions are a pproximately 2 inches b v 10 inches in cross section;the bottom of the pipe being left round and the broader ivalls at thetop thereof hence in effect gradually flaring apart as the round loverend is approached; the flare beginning from a pointpreferably about halfnay up the pipe, The retort thus formed is admirably adapted to theprocess since the heat from the oil burners 2 or the like does not haveto penetrate any great distance into the bulk of the reactive mass, atthe part of the retort to which the heat is most strongly applied,before it has reached the center or core thereof; nllhile the gradualincrease in cross sectional algea of the vertical retort from the pointtherein where 'the material being treated commences to become noticeablyplastic, tends to prevent the retort from becoming choked and hencefacilitates a continuous feed therethrough. The retort may be centrallydisposed in a suitable briclcwork furnace 3 which preferably tapers inat about half way up toward the top'thereof to form a. flue #l whichsurrounds the upper part of the retort and preferably conforms in shapethereto; a space of about 1% inches being provided all around betweenthe retort and the inner Walls of the flue. A delivering connection or T5 may be bolted to the flange at the upper end of the retort 6 inches ormore above the brick flue, to provide means for introducing materialinto said retort. Preferably, a screw conveyer 6 is used to deliverbriqueted material through the connection 5; the said material enteringthe conveyer from a hopper 7 The oil burners extend through suitableopenings in the furnace Walls and may have the flames thereof directedtoward the retort; it bein advisable in such case to provide a ha e orscreen 8 of fire brick or other suitable refractory material so as toAprevent the direct impingement of said flames against the side or sidesof the retort. In the present instance the baille is substantiallytubular with openings 8 in the sides thereof which are away from theliames.

5 The brick furnace may rest upon a cast iron plate 9 which in turn issupported upon columns 10 so to provide an air space below the furnaceproper into which the gradually rounding or llared lower end 1 of theretort extends. T he bottom of the retort is flanged and bolted to thearm of a.

cast iron lT 11 and the lateral arms of this T are respectively boltedto pipe sections 12 andl and together With a second T 14, se-

cured to the outer end of pipe 12.0onstitute a screw conveyer chamber,the screw 15 of which is mounted upon a shaft' 16 journaled at its lefthand end in a suitable thrust bearing head 17 and at its right hand endin a head 18 secured to T 14 and provided with a suitable stutling box19. The screw 15 is sloivly driven in any desired mannerI as by means ofa chain and sprocket 4drive 20 and the treated material conveyed therebyfrom the T 11 is delivered through the preferably downwardly directedarm of the T 14 through a T 21 to a suitable receptacle Q2. The cyanidcontaining material delivered to the latter may be collected therein andremoved in bulk or it-may be continuously removed by means of a screwconveyer 23; care being preferably exercised when the latter, oritsequivalent, is used to prevent any material quantity of air fromentering the retort therethrough since the oxygen content of' such airwould contaminate the product, e. g. by forming a cyanate or even somecarbonate of the element which constitutes the hase of the cyanogencompound sought.

Samples of the product may be taken off at 2i and the free nitrogen,preferably used, may be introduced through a pipe 25 which delivers toan annular pipe 2G disposed in the enlarged end Q7 of the upstanding armof the T l1. plate 23 covers the pipe 26 and shields it from thedescending mass of briquets and the enlargement 2T affords the freenitrogen, or the like, admitted at this point, a chance to quite freelyescape from the downwardly and outwardly directed apertures or vents Q9in pipe 26.

Within the retort 1 in Fig. 2 is shown a mass of briqueted material 30in course of treatment while the material 31 shown adjacent the screu l5has of course been subjected to the cyanid producingr reaction.

lt is important to note that the nitrogen delivered to the reactive massis preheated by its passage through the hot residues of said reaction,and that in like manner the briquets introduced through the hopper 5 arepreheated by the escaping gaseous products of such reaction; carbonmonoxid and someunconsumed nitrogen constituting the greater part ofthese gases and escaping, if desired, through the open upper end of thehopper The chilling of the solid reaction products while passing throughthe exposed and cooled portion l' of the retort and further by theirconta et with the relatively cool cur rent of nitrogen passing up intothe retort, is also of value in that it facilitates the removal of saidproducts from the retort, the briquets upon cooling losing theiracquired plasticity, while at the saine time the nitrogen is preheated.

Y The preheating of all of the participants of the reaction, when donein the manner indicated. not only saves fuel, but favors the efficiencyof the process; the reaction taking place practically as soon as a givenbulk of the solid material enters the reaction zone. and throughout theextent of said bulk; a feature of very great importance from acommercial standpoint. This manner of preheating the charge also enablesus to make use of the reversible equation:

(l) 2003002 C -l- 38,960 calories,

since, disregarding diluting gases, 96% CO is'Y would, in so far as itis effected, amount to roducinn cvanid according to the e nation: p b ub (2) NazCO3 +SZC+N2= ZNaCN UZCOZ 80,960 calories.

Comparison of this equation (2) with the following equation:

(3) Na()3 +4C+N2= 2NaCN+ SCO 138,500 calories which .is generally givenfor cyanid formation, shows these advantages and, the procedure, in anycase, has the additional advantages of avoiding the deleterious effectof C02 upon the produced cyanids, and of requiring less grinding ofcarbon because of the smaller quantity consumed.

Then iron scale, magnetite. hematite, etc., are used instead of metalliciron in making the briquets, the above effects may also be in evidence,and, in addition the iron. oxids will aid in changing the C() to CO2 inthe upper Zones of the vertical retort, as for example:

(i) reso4 ico are ico,

now strongly eXot-hermic, that the quantity of carbon required the sameas in equation that We can very readily get the gaseous product of thereaction substantially quantitatively in the form of CO2 without anyrisk of injurious action from this gas.

If it is desired to favor the formation of CO2 in the manner suggestedin equations 2 and 4, the upper partof vthe retort may be enlarged orelse connected with a hopper Y or reservoir which contains a largequantity of briquets at the proper temperature as in dictated in Fig. 5.These briquets (when sodium carbonate is used) will notbe hot enough tobe plastic, hence they can be handled easily and they will insure alonger vcontact with the gaseous reaction product considered, even wherea round pipe having a diameter of only 4t inches is used, I now preferto use pipes attened to afford a more or less rectangular or ellipticalcrosssection through at least a considerable extent of the lengththereof. Such a pipe as I have illustrated inFig. l combines theadvantage of easy feeding therethrough possessed by conical or slopingwalled pipes, larger at the bottom than at the top, with theadvantageous disposition of the reactive material to' permit of quickheat penetration to the middle of the still relatively thick bulk ofbriquets.

By an obvious modification of the arrangement at the base, acontinuously feeding lfurnace with concentric tubes or pipes 32 and 33,forming a .retort such as is indicated in Fig. a, may be constructed,these tubes readily adapting themselves tovarious modiications along thelines which I have just indicated; the retort proper being substantiallyannular in cross-section. This form of retort possesses the furtheradvantage that it permits of heating from both within and without sothat if the space between the concentric pipes be approximately 2inches, but about l inch of the briqueted material need be penetrated bythe heat in order to effect the desired reaction in the innermostportions thereof.

The types of furnaces which make provision for quick heating have agreat advan' tage in that they can be operated at a lower temperaturesince the rate of cyanid formation is shown by Experiment 10 to belargely dependent upon heat penetration and hence,

for given cyanid output, the temperature of the outside of the pipe orretort holding the charge need not be so high as in furnaces which donot permit of quick heating.

Cast iron retorts, it may be here noted, are adapted to easily withstandthe operat ing temperature, which should preferably be maintained belowthe eutectic point of the catalytic material, saturated, it is apt tobe. and indeed preferably is, with carbon, so that thisl reactivesolution surface may be maintained both physically as a surface and asregards the carbon content thereof, since if the temperature be undulyraised sintering or worse occurs in the body of the solid,

and preferably briqueted, material under.

the treatment.

Obviously other substances than iron lmay be used for cyanid productionin the construction of the reaction tubes or retorts; but as I havefound iron tubes very durable when heated in a reducing flame to therelatively very moderate temperature required by my process, I prefer touse such tubes on account of their comparatively low cost.

(La-,'68 other than pure atmospheric nitrogen available for theprocesar-finie in certain cases I prefer to use substantially purenitrogen, as I have indicated I may also use air: burning the oxygentherein, preferably to carbon monoxid before admitting it, or rather thehot residues of such combustion, to the charge to be treated. Further, Ihave quite successfully employed unpurified producer gas, in place ofatmospheric nitrogen, with a continuously acting furnace which containeda reaction pipe 6 inches in diameter by 10 feet long and Which moreoverdid not even have the chimney and hence had no `uovision for preheatingthe moving charge ei ther from the hot gases ascending inside or outsideof the retort. The producer gas was made by passing air which had notbeen dried, through coke heated to incandescence in an iron tube and insome cases the so prepared gas contained less than 1% of carvbon dioxid.It was led directly, and Without puritcation, to the cyanid producing:furnace and was used in the same Way as nitrogen. The resultingcyanided briquets were lixiviated and a solution was obtained having astrong yellow color such as I have noticed when working with nitrogeninto which inadvertently some oxygen had found its way. Also a scum oflampblack-like carbon was noted, which was apparently due to thedeposition of carbon according to the equation:

zoos-,cofre f the carbon dioxid formed according to the the damage isapparently caused bv the for mation of much carbon dioxid by reason ofthe comparatively low temperature and by the extended contact surface ofthe briquets;

and, this is made Worse by the fact that the 3 temperature is too 10Wfor the alkaline decomposition products to be converted back intocyanide. In spite of this, however, a tube of the above mentioned sizewill yield over 100 pounds of sodium cyanid in 2st hours Luider theconditions described.

The above troubles can be overcome by introducing the producer gas, orthe like, at the. base of the heat zone in the furnace itself in anysuitable manner and the tube or other receptacle in which the producergas, or the like` is generated may also be in the cyanid furnaceitself,y thus giving the advantage of the use of air, as in Experiment11., and highly preheated producer gas, combined with the advantageswhich reside in a continuously acting furnace.

While I have specifically mentioned certain free nitrogen containinggases, I do not desire to be limited to these, since I am aware thatmany commercial waste gases, such as those from a blast furnace, may beused instead of air or producer gas in effectuating my process. In theappended claims such an expression as free nitrogen is hence to beregarded as of sufficient breadth to cover free nitrogen no matter fromwhat suitable source supplied.

Drawings-Second Sheet.-Fig. 5 somewhat diagrammatically shows a'suitablefurnace adapted for the carrying out of mv process with. for example,producer gas. The tube or retort in which the briquets (or othersuitable form of cyanid producing charge) are placed, is shown to theright. This tube is preferably' enlarged at 3G so that the producer gasenteringr from a tube 37 can pass freely into the descending stream ofbriquets 38. Coke 39 is fed from a gas tight hopper 40 into a tube 41 bymeans of a screw or other conveyer 42: and tube 41 is further connectedwith an air tight receptacle 43 for receiving the ashes 44 resultingfrom the combustion of the descending column of coke in the tube 41. Asuitable conveyer 45 may be used to deliver said ashes to saidreceptacle 43. A short cross tube 4G connects the top of tube 41 withthe top of tube?? and a 'secondsuch tube or conduit 47 connect, the tube37, at substantially the bottom tirarmi. With the top of the enlargedpart 9,5 of the retort 35. When the. furnace is in operation. a currentof air. entering at 48, meets the descending charge of hot coke .in pipe41 at the base of the heat zene and there burns said coke to formproducer gas and ashes. The latter, while being removed by conveyer 45,prehcats the incoming air while the producer gas passes up through thepipe/41 and thence down through the incandescent coke 49 in pipe 3T, tothe counection 47, whence a portion at least thereof enters and ascendsthrough retort 35. Col-:e upon heating may give oif moisture and otheroxygen containing materials and hence the continuous introduction offresh coke at the top of pipe 41 would contaminate the producer gas withthese oxygen-containing volatile products. The incandescent coke in pipe37, however, serves to decompose such volatile products before they canenter the retort 35. As the coke in the tube or like receptacle 37 isused simply as a purifier, it lasts a long timey Without renewal. I haveindicated by arrows the direction of the gas currents through theapparatus shown, and have broken away sections of the pipes andconveyers so as to better diagrammatically indicate the nature of thecontents thereof. In both pipes 41 and 35, it will be observed, theincoming gas is introduced substantially at the base of the heat zone; afeature of great advantage both in so i' ar as the forma- Ation andheating of the producer gas is concerned and in that it overcomes thetroubles which, in the absence of this provision or its equivalent. areattendant upon the use of commercial producer gas or the like. Thebottom of the retort 35 below the suitably heated furnace 50, is, itwill be observed air cooled, as in the preceding case: but other meansfor cooling may be utilized. The briquets or the like may be introducedinto the retort 37 by means of a screw conveyer 51, also substantiallyas in the previously described apparatus. and the treated briquetsdelivered by the conveyer 52, corresponding to conveyer 15, may besuitably disposed of as in the form of apparatus previously described. Iprefer. in this mode of conducting my process, to provide an elon gatedhopper 53 as a reservoir from which are fed the briquets to the retortproper, and the gases ascending from the latter pass up through saidhopper to preheat the briquets therein as in the preceding case. As thecarbon-monoxid formed in the retort passes up into the cooler upperparts of the briquet conveying conduit ot which said retort and hopperJform parts, the lower tempt-ratiue permits the conversion of a veryconsiderable amount of said gas to carbondioxid as per rcuation l: thisaction being evialcrf: roi-mth farmed. as previously stated. lq. thecatalytic iron-carbon or i-quaicrfl surface in thel briquets. Theapparatus ioiin in Fig. 5 also allows` us to use a large excess ofproducer gas or its equivalent and to thus supply most or evenpractically all of the heat necessary for cyanid production. Thus asubstantially pure mixture of carbon inonoxid and nitrogen may be @ravinofi' from the bottom of the receptacle 37 throrfih a pipe 54 anddelivered to the retort 35 al'iove the reaction Zone through .'lieconnection The connection 47 should, of course. be so proportioned. orthe conduit. therein otherwise so controlled. as to permit of thedelivery of a proper amount of the gaseous mixture therethrough to thebase of the reaction zone despite this withdrawal of a considerableportion of the gas descending pipe 37 through pipe 54. Provision mayalso be made for the introduction of suitable carbon-monoxid orcarbon-monoxid and nitrogen containing gases from an extraneous source.such as. for example, a gas producer or blast furnace; such gases beingdelivered from pipe 56 direct through pipe 54 and connection 47 to thebase of the reaction zone or through pipe 55 to the retort above saidzone, or to the connection 46 via a pipe 57 and thence through theincandescent-coke containing receptacle 37, according to the nature andcondition of said gases and the requirements of the cyanid formingreactionr Various combinations of these gas entries and the regulationof the flow of gas through the several pipes is controlled by therespective valves 58, 59, 60 and 61. It is thus possible to not onlyconserve heat but, further. to deposit enough carbon, in especially goodcondition, upon and around the catalytic surface in the pores of thebriquets, to make up or even more than make up for the. carbon removedfrom the charge by the cyanid formation. according to equation 3. In allcases. of course, Where such deposition of carbon from the conversion ofcarbon monoXid to the dioXid is to be effected the briquet mass in theupper portion of the retort and in the conveyer 51 and hopper 53 (if thecarbon is to be deposited in the latter) should be maintained, byextraneously supplied heat if necessary, at a temperature sufficient topermit of the dioXid-forming reaction taking place effectively. Thistemperature should preferably be in the neighborhood of 500 C. to 600 C.This procedure, in which the briquets, to be used in the subsequentcyanogen-compound-forming reaction, act in a peculiarly advantageouscatalytic manner, makes it possible to supply carbon from gasescontaining carbon monoxid to lproduce an ashless carbon in Very finelydivided form and immediately and initially, so to speak, very closelyincorporated in or associated with the iron or like catalyzer employed.This mode of pro- )r the like with silicates, aluminates, etc., whenlixivation is employed.

The expression vapor constituting the source of a metal adapted to actas the base of a cyanogen compound, used in certain of the claims, is tobe regarded as of Sullicient breadth to cover not only alkali carbonateor a likeacting compound or compounds, but also sodium vapor or itsequivalent. The molecules ofl this vapor when supplied by thevolatilization of the sodium carbonate embodied in the briquets or thelike, have but relatively extremely short distances to travel afterliberation before they impinge against some portionv of the ramiied andgreatly extended catalytic solutin surface which permeates the mass ofthe briquets. In fact the briquets described, the Walls of ,each of thepores thereof are in large part composed of the carbon dissolvingmaterial and the remainder of such Walls largely consist of carbon andthe said sodium carbonate; the latter serving notonly as the source ofsaid vapor but further,

25 as previously intimated, as a binder for the carbon and catalyticmaterial, whereby to hold the carbon so closely in contact with saidmaterial as to permit of the constant renewal of the carbon in solutiontherein as the latter is removed by the cyanid forming reaction. It islargely for this reason,

too, that care in the temperature regulation must be exercised in orderto preserve; not

only vthe catalytic iron, for example,` in

proper condition, avoiding sintering thereof which destroys its extendedsurface; but

further to avoid unduly heating portions of the bulk of conglomeratebeing treated in such fashion as to cause an unequal consumption or evenwasteful volatilization of the sodium carbonate, or equivalent, binder,

which would permit of the subsequent'disintegration of the briquets atsuch portions in the manner above set forth, even despite the cooling ofthe solid residues by the relatively cool nitrogen current or byextraneous means, or both.

In certain of the appended claims it is specified that there is used inthe process a metal or element which is capable of dissolving carbon.and where in such claims it not specifically stated 'that the carbonparticipating in the reaction is in solution in such metal or element.said claims`are to be regarded as of sufficient breadth to cover saidcarbon whether in, solution in or in combination with said metal orelement.

"llius, iron is capable of dissolving carbon but when the reaction iseii'ected the carbon n may be and preferably isl'in solution therein: orit may be combined therewith Vto form a carbid. Where, also, in certainof the other claims it is specified that said metal or element iscapable of combining with carbon, such expression is intended to covernot only carbid forming metals. or the like, but such element or metalalready combined With carbon, as in a carbid, and further metals, suchas iron, which are capable of dissolving carbon or which may have carbonalready in solution therein; the Word combining being used as a genericterm for all fo is of chemical combination 0r solution, of e classes incuestion. Still further, Where reference to the catalyzer is l omittedin any of the claims I desire it to be understood that such omission isintentional; so that in such cases the catalyzer, iron, or thelike, isnot be read into said claims. Finally, I desire to point out that bymeans of the foregoing process involving the conversion of carbonmonoxid generated in the process, to carbon dioxid, it is possible toobtain argon from the atmosphere very economically. Thus carboncontaining g5 gases which issue from the cyanid forming mass may beremoved` e. g., by oxidizing them completely to carbon'dioxid and thenabsorbing the latter in any suitable known manner. -This hence gives aneconomical method of separating the inert gases, principally argon, fromatmospheric nitrogen through the removal of the latter during the courseof the cyanid forming process. This latter process may be repeated Withthe residue, and in any case the residual gases will become enriched inargon.

Having thus described my invention what I claim is: y

1. The process of fixing nitrogen Which comprises passing a current ofgaseous matter, a portion at least of which is free nitrogen,substantially evenly through the pores and interstices of a relativelylarge bulk of briqueted material which includes carbon and an elementcapable of dissolving carlbriqueted material in such form as to presentan extended catalytic surface to said gaseous matter, said briquetedmaterial also having an initially combined .base-forming element thereinwhich is capable of being combined with the carbon in said surface andwith said nitrogen to form a cyanogen compound of said base-formingelement, and effecting a. reaction in which participate saidfreenitrogen, carbon and base-forming element, to form said cyanogencompound.

2. The process of fixing nitrogen which comprises passing a current ofgaseous matter, a portion at least of which is free nitrogen, throughthe pores and inteistices of a relatively large bulk of briqueedmaterial which includes carbon and an element caF pable of dissolvingcarbon. said element being present in said briqueted material in suchform as to present an extended catalytic surface to said gaseouslmatter, said briqueted material also having an initially combinedbase-forming element therein iSv which is capable of being combined withthe carbon in said surface and with said nitrogen to form a cyanogencompound of said base-forming element and e'ecting a reaction in whichparticipate said free nitrogen, carbon and base forming element, to formsaidcyanogen compound, the said bull: of material being subject duringthe course oi' the operation to a force adapted to compact the same andprevent vthe formation of conduits therein through which the gaseousmatter may too freely escape.

3. The process of fixing nitrogen which comprises. passing a current ofgaseous matter, a portion at least of which is free nitrogen, underpressure substantially evenly through the pores and interstices of arelatively large bulk of material which includes carbon and an elementcapable of dissolving carbon, saidelement being present in said materialin such form as to present an extended catalytic surface to said gaseousmatter, said material also having an initially combinedbase-formingelement therein which is capable of being combined with the carbon insaid surface and with said nitrogen to form a cyanogen compound of saidbase-forming element, and eliecting a reaction, at a temperature ofabout 10000 C., in which participatesaid free nitrogen, carbon andhase-forming element. to form said cyanogen compound.

el. The process of fixing nitrogen which comprises subjecting a porousbulk of ma- -terial which includes carbon, an element capable ofdissolving carbon and a second element capable of acting as the base ofa' cyanogen compound under the conditions of the operation` to theaction of heat, and so disposing said bulk of material and applying theheat thereto as to insure an equable distribution of the latterthroughout a reaction zone in said bulk of material in which is presentan extended surface ot' said carbon dissolving element, passing acurrent ot gaseous matter, a portion at least of which is free nitrogen,under pressure substantially evenly through the pores of said materialin said zone and thereby eii'ecting a reaction in which activelyparticipate the said carbon, free nitrogen and said second mentionedelement, to form said cyanogen compound.

5. The process of fixing nitrogen which comprises subjecting a porousbulk of bri queted material which includes carbon, an element capable ofdissolving carbon and a second element capable of acting as the base ofa cyanogen compound under the conditions of the operation` to the actionof heat, and so disposing said bulk of briqueted material and applyingthe heat thereto as to insure an equable distribution of the latterthroughout a reaction zone in said bulk of briqueted material in whichis present an extended surface of said carbon dissolving element,passing a current of gaseous matter, a portion at least of which is freenitrogen, under pressure substantially evenly through the pores of saidmaterial in said zone and thereby eifecting a reaction in which activelyparticipate the said carbon, free nitrogen and said second mentionedelements, to form said cyanogen compound.

6. The process of fixing nitrogen which comprises subjecting a porousbulk of material which includes carbon, an element capable of dissolvingcarbon and a second element capable of acting as the base of a cyanogencompound under the conditions of the operation, to the action of heat,and so disposing said bulk of material v'and applying the heat theretoas to insure an equable distribution of the latter 'throughout areaction zone in said bulk of material in which is present an extendedsurface of said carbon dissolving element, passing a current of gaseousmatter, a portion at least ot' which is free nitrogen, under presuresubstantially evenly through the pores of said material in said zone andthereby effecting a reaction in which actively participate the saidcarbon, free nitrogen and said second mentioned elements, to form saidcyanogen compound, and causing successive portions of said material toadvance through said reaction zone.

7. rl`he process of fixing nitrogen which comprises subjecting a porousbulk of material which includes carbon, an element capable of dissolvingcarbon and a second ele ment capable of acting as the base of a cyanogencompound under the conditions of the operation, to the action of heat,and so disposing said bulk ot material and applying the heat thereto asto insure an equable 4distribution of the latter throughout a reactionzone in Said bulk of material in which is present an extended surface ofsaid carbor dissolving element, passing a current of gaseous matter, aportion at least of which is free nitrogen, under pressure substantiallyevenly through the pores of said material in said zone and therebyeffecting a reaction in which actively participate the said carbon, freenitrogen and said second mentioned elements, to form said cyanogeucompound, and causing successive portions of said matcrial to advancethrough said reaction zone by the action of gravity.

S. The process of ixing nitrogen which comprises subjecting a porousbulk of material which includes carbon, an element capable of dissolvingcarbon and a second element capable of acting as the base of a cyanogencompound under the conditions of -the operation'. to the action of heat`and so disposing said buik of material and apply ing the heat thereto asto insure an equable distribution of the latter throughout a reactionzone in said bulk of material in which is present an extended surface ofsaid carbon dissolving element, passing a current of gaseous matter, aportion at least of Which is free nitrogen, under pressure substantiallyevenly through the pores of said material in said zone and therebyeffecting a reaction in which actively participate the said carbon, freenitrogen and said second mentioned elements, to form said cyanogencompound, and causing successive portions of said material to advancethrough said reaction zone While preheating said portions previous totheir entrance into said zone.

9. The process of fixing nitrogen which comprises subjecting a porousbulk of material which includes carbon, an element capable of dissolvingcarbon and a second ele ment capable of acting as the base of a cyanogen compound under the conditions of the operation, to the action ofheat, and so disposing said bulk of material and applying the heatthereto as to insure an equable distribution of thelatter throughout areaction zone in said bulk of material in which is present an extendedsurface of said carbon dissolving element, passing a preheated currentot' gaseous matter, a portion at least of which is l'rce nitrogen, underpressure through the pores of said material in said zone and there b vefi'effting a reaction in which actively participate the said carbon,free nitrogen and said second mentioned element, to form said cyanogencompound.

l0. The process of fixing nitrogen which .includes forming an extendedcatalytic solution .surface comprising carbon dissolved in a metal inthe solid phase which is capable ci' rendering said carbon reactive forarticipation in the ensuingreaction, and feeding thc so Jlissolvcdcarbon by gravity through a heated reaction zone, together With-a sub`stance which is capable of' being vaporized and of acting as the sourceof a metal adapted to become the base of a cyanogen ompound formed bysaid reaction, and supplying preheated free nitrogen to said Zone tothereby form said cyanogen compound.

l1. The process of iixing nitrogen Which includes forming an extendedcatalytic solution surface comprising carbon dissolved in a metal in thesolid phase which is capable of rendering said carbon reactive forparticipation in the ensuing reaction, and feeding the so dissolvedcarbon by gravity through a heated reaction Zone, together with asubstance which is capable of being vaporized and of acting as thesource of a metal adapted to become the base of a cyanogen compoundformed by said reaction, and supplying preheated free nitrogen to saidzone equally throughout substantially the extent thereof to thereby formsaid cyanogen compound.

in a metal in the solid 12. The process of fixing nitrogen whichincludes forming an extended catalytic solution surface comprisingcarbon dissolved phase which is capable of rendering said carbonreactive for participation in the ensuing reaction, and feeding the so'dissolved carbon by gravity into a heated reaction zone, together With asubstance which is capable of acting as a source of a metal adapted tobecome the base of a cyanogen compound formed by said reaction,supplying free nitrogen equably to said zone to thereby form saidcyanogen compound, and preserving substantially intact and effectivesaid solution surface by temperature regulation While supplyingadditional carbon thereto as needed.

13. The process of fixing nitrogen `Which comprises subjecting reactivecarbon, dissolved in a metal in the solid phase presenting an extendedcatalytic solution surface, to contact with preheated fre'c` nitrogenand a substance capable of yielding, during the course oi the ensuingreaction, a metal adapted to act as the base of a cyanogen compoundstable at the temperature of the operation, effecting said reactionthrough the intermediacy of heat, and removing the residues from thezone of said reaction, drectly thereafter.

lit. The process of fixing nitrogen which comprises subjecting preheatedreactive carbon, combined with a metal in the solid phase presenting anextended catalytic s0- lntion surface, to contact with preheated treenitrogen and a substancfY c: )a ,e of yielding, during the course of theensuing reaction, a metal adapted to act as the base oi a cyanogencompound stable at the temperature of the operation, effecting saidrekaction through the intermediacy of heat,

and removing the residues from the one of said reaction, directlythereafter.

15. The process of fixing nitrogen which comprises subjecting reactivecarbon, coinlined with a metal in the solid phase presenting an extendedcatalytic solution sur face, to contact with preheated free nitrogen anda substance capable of yielding, during the course of the ensuingreaction, a metal adapted to act as the base of a cyanogen compoundstable at the temperature of the cpemtion, effecting said reactionthrough the ii'itermediacy of' heat, and continuously removing' theresidues from the zone of said reaction.

16. The process of fixing nitrogen which comprises forming porousbriquets throughout the pores of which is present an extended catalyticsurface of metal capable of rendering carbon reactive for participationin the ensuing reaction, said briquets also including carbon and acompound of a metal capable of acting as the base of a cyano en compoundto be formed by said reaction,

com; is :ormiug porous briquets throughout da.; poles oi" wlnch 1spresent an ex trud analytic sui-tace ol' metal capable of carbonreactive ior participation in ci.. ig reaction, said briquets alsoincluding carbon and a compound of a metal capable of acting the base ota cyanogen compound to lie formed by said reaction, said compound ot'said metal adapted in part at least to act as a binder for the remaining` material ot said briquets, preheating said briquets, subjectingthe same while hot to the action oi free nitrogen, whereby to iloruisaid cyanogencompound, and preserving substantially' intact, bytemperature regulation, the said briquets and the solu tion surfacetherein.

18. The process o fixing nitrogen which includes continuously supplyingto a heated reaction Zone, porous briquets, comprising a rainilied andextended catalytic solution surface oit' a metal capable of renderingcarbon reactive for participation in the ensuing reaction said surfacetogether with carbon constituting in large part the wa ls of the poresin said briquets, rendering said briquets plastic by heat in said zonewhile maintaining the pores thereol accessible to gaseous and vapor-ousmatters, and eleeting an impingement of free nitrogen molecules togetherwith those of a vapor constituting the source of a metal adapted to actas the base of a cyanogen compound, to be formed in said reactive zone,against said solution surface in said pores, whereby to form saidcyanogen compound.

19. The process of fixing nitrogen which includes continuously7supplying to a heated reaction Zone, preheated porous briquets,comprising a ramitied and extended catalytic solution surtace of a metalcapable ot rendering carbon reactive for participation in the ensuingreaction said surface together with carbon constitutingin large part thewalls of the pores in said briquets, rendering said briquets plastic byheat in said zone While maintaining the pores thereof accessible togaseous and vaporous matters, and etfecting an impingement oi treenitrogen molecules together with those of a vapor constituting thesource of a metal adapted to act as the base of a cyancgeu compound, tobe formed in said reactire zone, against said solution surface in saidporcs, whereby "to form said cyanogen compound.

l20. The process of iixing nitrogen which includes continuouslysupplying to a heatfd reaction zone, porous briquets, comprising aramilied and extended catalytic solution surface of a metal capable ofrendering carbon reactive for participation in ihe ensuing rcaction,said surface togethe' with c i l constituting in large part the walls orpores in said briquets, rendering said briquets plastic by heat in saidzone while maintaining the pores thereof accessible to gaseous andvaporous matters, and eliiecting an impingement of previously andseparately preheated free nitrogen molecules together with those of avapor constituting the source of a metal adapted to act as the base of aeyanogen compound, to be formed in said reactive zone, againstsaidsolution surface in said pores, whereby to form said eyanogen compound.

2l. The process of tixing nitrogen which includes continuously supplyingto a heated reaction zone, preheated porous briquets, comprising aramitied and extended catalytic solution surface of a metal capable ofrendering carbon reactive for participation .in the ensuing reactionsaid surface together with carbon constituting in large part the wallsof the pores in said briquets, rendering said briquets plastic by heatin said zone while maintaining the pores thereof accessiblc to gaseousand Vaporous matters, and efectin(r an impingement of previously andseparately preheated free nitrogen molecules together with those of aVapor constituting the source of a metal adapted to act as the base of acyanogen compound, to be formed in said reactive zone, against saidsolution sui-lace in said pores, whereby to form said cyanogen compound.

The process of fixing nitrogen which includes continuously supplying toa heated reaction zone a column ol" porous briquets comprising arainilied and extended catalytic solution surface ot a metal capable olirendering carbon rcactirc for participation in the ensuing reaction,said surface constituting in large part the walls ci: the pores of saidbriquets and the remainder ol said walls being composed principally, atleast, ol' carbon and a compound the i ,e ol which is a metal capable ofi'ormimY .'.e base ol a .stable cyanogen compound duitng the col` rseol'V the reaction eii'erled in sail?. zone, maintaining said poresaccessible to g-.isemis and yaporous matters. and liowing a current otgaseous matter consisting. in part at least, of `free nitrogen throughsaid rcrartioi 1. zone, whereby to form said cyanogen compound.

;l. The process ot fixing nitrogen which comprises subjecting a porousbulli' o' bri quoted material which includes carbon, an element capableof combining with bon and a second element capable o. as the basof acyanogen comporud op the conditions of the operation. to the a oi' heatin a reaction zone in said materiwhich is present and maintained an eXtended carbon containing catalytic surface of said firstclement,'equably distributing said heat in said zone and introducing arent of gaseous matter, a portion at least of which free nitrogen, atsubstantially the hase of said Zone, whereby to effect a reaction in.which the carbon in solution in said surface, said free nitrogen andsaid second clement activeljiY participate to forni said cyanogencompound.

il. The process of fixing nitrogen which coinprises subjecting a hotmoving mass comprising briquets in each of which is present an extendedsurface composed of carbon in combination with a catalyzer capable ofrendering said carbon reactive, to contact. with free nitrogen, whilevaporizing in said mass a substance which is capable of yielding, underthe just recited conditions, an clement adapted to act as the base of acyai'iogen compound stable at the temperature of the operation,effecting a, reaction in which participate said carbon, nitrogen andclement, and thereafter lowering the teinperature of the reactive massduring a further mowment thereof, whereby to substantially preserve saidbriquets.

The process of fixing nitrogei which comprises so subjecting a hotmoving mass of diminutive porous briquets, in i bien mass, as a Whole,is present an extendef surface composed of carbon in combi tion with acatalyzer capable of rendering said carbon reactive, to contact withfree nitrogen, as to freely introduce said nitrogen into said poresWhile the latter contain an eienient in condition to react with saidnitro gen and with said carbon to form a cyanogen compound the base ofWhit u is said element, and regulating the temperature of said movingmass throughout the extent thereof so as to preserve said briquetssubstantially intact. y

26. The process of fixing nitrogen Which comprises so subjecting a hotmoving mass of porous briquets, in which mass, as a whole, is present anextended surface composed of carbon in combination With cat alyzercapable of rendering said carbon reactive, to contact with freenitrogen, as to freely introduce said nitrogen into said pores while thehitter contain an element in condition to react with said nitrogen andwith said carbon toform a cyanogen compound the base of which is saidelement, and regulating the temperature of said moving mass throughoutthe extent thereof so as to preserve said briquets substantially intact.

27. The process of fixing nitrogen which comprises establishing a heatednon-sintermg reaction zone and moving a mass of catalytic briquetedmaterial.constituents of i which are capable of reacting with freenitrogen to form a cyanogen compound,

through said zoneI under cyanogen coinpound orming conditions, loweringthe temperature of said briqueted material after it leaves said zone,supplying the free nitrogen needed 'for the cyanogen-compoundforrningreaction mixed with carbon monoXid and introducing such gaseous mixtureinto said mass of briqueted material at points inA the course of thelatter when the temperature of said Ymaterial has not been n loweredsufficiently 'to permit of the conversion by an equilibrium reaction ofany con-- siderable portion of said monoxid to carbon dioxid.

28. The process of fixing nitrogen which comprises establishing a heatedreaction zone and moving anlass of briqueted material constituents ofwhich are capable of reacting with free nitrogen to form a cyanogencompound, through said .zone under cyanogen compound forming conditions,lowering the temperature of saidbriqueted material after it leaves saidzone, supplying the free nitrogen needed for the cyanogencompound-forming reaction mixed with car bon monoxid, introducing such gaseousmixture into said mass of briqueted material at points in the course ofthe iatter Where the temperature of said material has not been loweredsutiiciently to permit of the conversion by an equilibrium reaction ofany considerable portion of said monoxid to carbon dioXid and convertingsaid carbon monoxid to carbon dioXid Within said mass at points ivheresaid dioXid is unable to del eteriously affect the cyanogen compoundtoi-ined.

3?. The process of lining nitrogen which comprises establishing a heatedreaction zone and therein effecting a reaction in which participateoxygen, reactive carbon, free nitrogen and an element capable of actingas the base of a cyanogen compound which shall be stable at thetemperature of said zone, whereby to form carbon monoxid and saidcyanogen compound. and there` after so converting said carbon monoxid tocarbon dioxid as to permit of the utilization of the heat evolved bysaid last rcac tion, in said reaction zone.

3'. rihe process of fixing njirogen which includes forming a mixture ofatmospheric nitrogen and an oXid of carbon, purifying said mixture bybringing it into contact with incandescent carbonaceous matter toeliminate deleterious impurities therefrom, introducing the resultinggases into a reaction zone in which are present dissolved carbon and acompound of a metal capable of acting as the base of a. cyanogencouipound to be formed in said zone, equably distributing said resultinggases through said zone, substantially equably heating the materialstherein, whereby to form said cyanogen compound, cooling the solidresidues of the cyanogen-compound-forming reaction and deterring thesaid oxid of carbon from gaining access to said cooled residues.

31. The process of fixing nitrogen which includes forming a mixture ofatmospheric nitrogen and an oxid of carbon, introducingr Said mixtureinto a reaction zone in which are present dissolved carbon and acompound of a metal capable of acting as the base of a cyanogen compoundto be formed in said zone, equably distributing said mixture throughasid zone, substantially equahlv heating the materials therein. Wherebvto form said cyanogen compound, cooling the solid residues of thecyanogen-compound-forming reaction, and preventing the said oxid ofcarbon from gaining access to said cooled residue.

82. The process of ixing nitrogen Which comprises subjecting a stream ofporous briquets in which are present finely divided carbon and acarbonate of a metal adapted to act as the base of a cyanogen compoundto be Jformed during the course of the process and which carbonate acts,in part at least, as a binder for the briqueted material, to the actionof free nitrogen in a heated reaction zone, rendering said briquetsplastic by heat, effecting a reaction in said zone yielding saidcayanogen compound and carbon monoxid, and lowering the temperature ofsaid briquets after said reaction has been 'effected therein, whereby topreserve the integrity of said briquets While conducting said carbonmonoxid away from said zone in a direction substantial] y contrary tothat in Which said stream ol2 briquets is moving.

33. The process of fixing nitrogen which comprises subjecting a stream oporous briquets in which are present finely divided carbon and an oxygencompound of a metal adapted to act as the base of a cyanogen compound tobe formed during the course of the process and nhich oxygen compoundacts, in part at least, as a binder for the briqueted material, to theaction of free nitrogen in a heated reaction zone, rendering saidbriquets plastic by heat, effecting a. react-ion in` said zone yieldingsaid cyanogen compound and carbon monoxid, and levering the temperatureof said briquets ai'tcr said reaction has been effected therein,wlieieby io preserve thc integrity of Suid bl-nuatg, whie conductingsaid carbon monoxid away from said zone in a direction substantiallycontrary to that in which said stream of briquets is, moying.

i-i-, The process ci fixing nitrogen which gimprises treating abiiqueted porous mass, in the peres oi which is present a solvent forcarbon, with a carbonaccous gas,4 at a temperature at which said gas isat least in part unstable, whereby to deposit carbon 1n aplel of thispatent may said pores and dissolve the same, and reacting upon saiddissolved carbon. at 'a biglie" temperature, with free nitrogen and aniet. capable of acting as the base or' a stable cyanogen compound, toform said cyanogen compound.

35. The process oi "King nitro comprises, treating a poi-ous contains acompound of a capable of acting as the b cyanogen compound, to esta:tion Zones therein` subifictingr one zone to a carbona( ous l is anddeposi ing carbon from said ,f .s in the pores or' the mass ivithin saidzone. and then eliecting a cyanogen-compound-forming reaction in saidsecond zone, in which participate said carbon, free nitrogen and saidmetal.

36. The process of lining nitrogen vfhich comprises, treating a porousmass which contains a compound or' a metal which is capable of acting asthe base of a stable cyanogen compound, to establish two reaction zonestherein, subjecting said mass in one zone to a carbonaccous gas anddepositing carbon from said gas in the pores ot' the mass within saidzone, moving said mass from said iirst to said second Zone by gravityWhile elevating the temperature thereof, and effecting acyanogen-compound-forming reaction in said second Zone, in whichparticipate said carbon, free nitrogen and said metal.

37. The process of fixing nitrogen which comprises intimately mixingcarburizable metal in finely divided condition with two substances oneof which is capable of sup-- plying carbon to said metal to carbonizethe same and the other of which is an oxygen compound of an elementcapable of acting as the base of a cyanogen compound, pressing saidmixture into briquets to establish eiiicient contact conditions betweensaid carburizable metal and said substances, carburizing said metal inpart from carbon supplied from said carbon supplying substance and inpart by passing carbon-monoxid thereover at a temperature at which aconsiderable part of said monoxid will be converted into carbon dioxidand thereby deposit carbon in said briquets, whereby to reduce thequantity of ash which may be formed therein, and etl'ecting acyanogencompound-forming reaction which removes carbon from saidcarburized metal, by treating said briquets with free nitrogen in aheated reaction zone.

In testimony whereof I have aliixed my signature, in the presence oftvvo Witnesses.

JOHN E. BCHER.

Witnesses NORMAN E. No'rT, HOWARD C. RIPLEY.

be obtained for ve cents each, by addressing the Commissioner ofPatents.

Washington, D. C."

